Over the next 15 months, Britain's political debate will focus heavily on the prospect of a breakthrough by Ukip at the 2015 general election. For a new and untested party, however, overcoming the barriers of a first-past-the-post electoral system will be incredibly difficult, never mind competing successfully against three established and well-resourced parties that can each trace their roots back over a century. Aside from these wider challenges that meet all new parties in British politics, Nigel Farage and Ukip also face more specific problems.

Over the past year, and for our book Revolt on the Right, we investigated the backgrounds and concerns of over 100,000 British voters, including almost 6,000 who intend to support Ukip. Contrary to the conventional wisdom, which would have you believe that the average Ukip voter is a relatively secure, middle-class Conservative who is motivated only by their distrust of Brussels and perhaps also David Cameron, the true nature of this support is quite different; old, working class, poorly educated, male and driven by intense concerns not only about the EU but how Labour and the Conservatives have managed immigration, the financial crisis and the state of our politics more generally. These are voters who have been shaped by the social and economic changes over the past five decades, and who hold a fundamentally different set of values; they see a world and a way of life slipping away, feel powerless to stop it happening, and are angry at the established political class for not seeming to understand their concerns, or care about what is being lost. These intense beliefs are not likely to be resolved by a new party leader, a referendum promise or a net migration target. Ukip's revolt has been a long time coming, and it may have a long way to run yet.

But our analysis also sheds light on several groups in Britain that Ukip needs to win over if it is to mobilise a truly historic revolt, but who are currently resistant to Farage's charms. First, Ukip currently has little or no appeal among the half of the British electorate who do not share their intense hostility towards the EU. That non-Eurosceptics do not find Ukip appealing is fairly obvious, but it is also a problem for the party; even when voters share their intense concerns over immigration and the state of politics but are not animated by the EU, they remain unwilling to back Farage; 95% of Ukip voters disapprove of Britain's EU membership but fewer than one in 200 who think otherwise back the party. In other words, Ukip's anti-EU image is so strong that it is preventing them from winning over a far larger pool of voters who share their resentment of immigration and mainstream politicians but do not stay awake at night worrying about the EU.

Second, Ukip is consistently failing to win over three large groups of voters; the young, women and ethnic minorities. Women are the largest of these groups and though many share Ukip's views over Europe, immigration and threats to national identity, they are significantly less receptive than men. Almost 60% of Ukip's electorate is male, making it the most male-dominated of all parties (only the BNP, in earlier years, had a stronger male bias). Ukip has sought to present women candidates, notably in parliamentary byelections and on Question Time, but the party remains hampered by this "gender gap".

The story with ethnic minorities, meanwhile, is to be expected; just 0.4% of Ukip's electorate is non-white. Put another way, only one out of every 250 Ukip supporters is not white. The equivalent figure for Labour is 3.7%, and for the Liberal Democrats 1.7%. That Ukip's revolt is overwhelmingly white will not come as a surprise, although it is interesting to note that many rightwing parties are grappling with the same problem (the equivalent figure for the Conservatives is just 1.1%). But amid an era of rapidly rising ethnic diversity, this and another problem raises questions over the long-term sustainability of this insurgency.

Ukip is also a very grey revolt, which adds another dark cloud over its long-term prospects – although, of course, generational change takes a long time! In fact, 57% of Ukip's supporters are over the age of 54 but only one in 10 are under 35. During one of our interviews with Farage the Ukip leader recognised this specific problem, conceding that his party is "not connecting with disaffected youth". He is right. While young Britons have struggled amidst the crisis, they are also much less concerned about Ukip's agenda of immigration, the EU and rapid social change, and feel broadly comfortable with the identity and values of modern Britain. They have only ever known Britain as an EU member state, and our society as one of mass migration, much of which has come from the EU. The students we teach at our universities, for example, were born between 1993 and 1995, and most likely went to school alongside EU or non-EU migrants. They simply don't know anything else, and most likely think that Ukip's world view is markedly out of touch with their own experiences.

Ukip's revolt on the right is recruiting significant support among specific groups, but it is not one of unbridled potential. Like all political parties, Ukip faces some big challenges going forward that will need to be overcome if it is to meet its ambitions of causing a more damaging earthquake in British politics. Much rests on the shoulders of Farage, and on the next 15 months.

Revolt on the Right: Explaining Public Support for the Radical Right in Britain, a new book by Matthew Goodwin and Robert Ford, is published this week